32. Persons who use tobacco and strong drink sometimes become blind, because these poisons injure the nerves of sight. The ears are frequently injured by the use of tobacco. Smoking cigarettes and snuff-taking destroy the sense of smell. The poison of the tobacco paralyzes the nerves of taste so that they cannot detect flavors. Tea-tasters and other persons who need to have a delicate sense of taste do not use either alcohol or tobacco.
SUMMARY.
1. We have five special senses—hearing, seeing, smelling, tasting, and feeling.
2. The ear is the organ of hearing, and has three parts, called the external ear, the middle ear, and the inner ear. The inner ear contains the nerve of hearing.
3. The middle ear is separated from the external ear by the drum-head. The drum-head is connected with the inner ear by a chain of bones.
4. Sounds cause the drum-head to vibrate. The ear-bones convey the vibration from the drum-head to the nerve of hearing.
5. To keep the ear healthy we must avoid meddling with it or putting things into it.
6. The eye is the organ of sight. The chief parts of the eye are the eyeball, the socket, and the eyelids.
7. In the eyeball are the pupil, the lens, and the nerve of sight.
8. The eyeball is moved in various directions by six small muscles.